A sash is provided to the upper section of a door body section of a vehicle door. The sash is a member capable of supporting a closed window panel, and comprises a main sash constituting the outer frame of a door, and an auxiliary sash provided in auxiliary fashion to a portion of the main sash. Patent Literature 1 is prior art related to such a vehicle door.
In a vehicle door such as that indicated in Patent Literature 1, a main sash and auxiliary sash are provided above the door body. The auxiliary sash is mounted so that the upper end abuts the main sash and is open in a substantially U-shaped (substantially C-shaped) configuration toward an openable/closable window panel. In other words, the auxiliary sash includes a vehicle interior wall on the vehicle interior side, a vehicle exterior wall on the vehicle exterior side, and a bottom wall that connects the vehicle interior wall and the vehicle exterior wall. Notches are formed in the upper ends of the U-shaped corners. In other words, a notch is formed in the upper end of the boundary between the vehicle interior wall and the bottom wall, and in the upper end of the boundary between the vehicle exterior wall and the bottom wall. These notches are formed to facilitate cutting for abutting the auxiliary sash against the main sash. A run channel for supporting the window panel is fitted into the substantially U-shaped auxiliary sash.
However, when water has made contact with the vehicle door, some of the droplets that have migrated along the door panel or the like may penetrate to the inner surface side of the substantially U-shaped auxiliary sash from the notches. The droplets that have penetrated to the inner surface side may seep out from between the run channel and the auxiliary sash to the distal end of the vehicle exterior wall or the vehicle interior wall. In particular, the vehicle interior wall is a location near the passenger compartment, and water seepage must be more reliably suppressed.
At this point, it is possible to consider disposing a sealing member so as to surround the notch on the vehicle interior side, or using a run channel with good sealing characteristics. However, when such countermeasures are used, component costs are increased and the cost of the vehicle door overall is increased.